Carts are used to transport items in commercial establishments, such as groceries in supermarkets and luggage in airports. Customers place their items into such carts in order to transport the items to their parked vehicle or other destinations. When customers are done with the carts, the carts are placed in central collection areas or simply left unattended. Often the central collection areas serve as rental and return stations such that the customer is reimbursed for returning a cart.
Unattended carts pose problems. Many existing carts do not have brakes. These unrestrained carts can roll freely and cause damage to both persons and property. This is of particular concern on train platforms, where an unrestrained cart can cause damage to the transportation system. The carts themselves also sustain damage thereby reducing the useful life of the cart. Therefore a brake system is needed that automatically engages when the cart is left unattended in certain installations.
Several attempts have been made to employ brakes in cart. Most existing cart brakes operate against the tire tread of a cart wheel. This has several disadvantages. For example, the tire tread can become abnormally worn down, reducing the traction and ultimate safety of the cart. As the tread wears, brake performance is diminished. In addition, the wheels must be replaced at regular intervals which increases the overall cost of maintaining carts. Also, brake mechanisms acting on the outside of the wheel are more susceptible to damage, e.g., the brakes can be easily struck by a foreign object such as a foot or other carts. In addition, tire treads have a tendency to pick up debris, water and other contaminants which can damage and reduce the overall effectiveness of the braking mechanism. Therefore a need exists for a durable brake which will not degrade the tire nor reduce the operational safety of the cart.
Further, nestable carts place certain demands on the braking system. First, the braking system must be compatible with the typical rental-return station. A common type of rental-return station accepts the rear wheel of a cart through a guided wheel slot. The wheel fits snugly within the slot, and the slot opening is locked to prevent unauthorized access. Brake arrangements that operate by engaging the tire tread are typically positioned on the outside of the wheel, and do not easily fit within the guided wheel slot. Even if the brake fits within the slot, it is highly susceptible to damage by the guided wheel slot.
Another requirement of nestable carts is the release of the braking mechanism. Carts are often nested together and returned to a central collection area in a long train arrangement. When the carts are nested, all brakes must be released in order to transport the train arrangement.
Therefore, a need exists for a durable cart brake mechanism that will automatically engage when left unattended, and be configured for receipt within guided wheel slots of return stations. The brake must also disengage when nested with another cart to facilitate en masse cart movement.